The present invention relates to a light emitting diode (LED) device used in an electronic equipment such as a personal computer, printer, PDA, facsimile machine, pager and a portable telephone.
In recent years, a liquid crystal display (LCD) having a back light is widely used as an illuminating panel device for illuminating various electronic equipments such as a notebook computer having an optical communication device, a PDA and a portable telephone. As an electronic equipment provided with such an LCD, an LCD back light for a portable telephone and an LED for illuminating various keys of a portable telephone are widely used.
FIG. 6 is a front view showing a conventional portable telephone disclosed in the Japanese Patent Application Laid Open 2002-24811. The portable telephone 10 has an LCD 11, three LED packages 12 for the LCD 11, a plurality of key switches 13, and a plurality of LED packages 14 for illuminating the key switches 13. The LED package has an LED chip mounted on a circuit substrate made of glass epoxy resin, the LED chip is encapsulated by a transparent or translucent resin. In the conventional device, a number of LED packages must be provided, since the conventional LED package is inferior in directivity. Therefore, there is a problem that the conventional device can not satisfy demand for low cost.